In the packaging industry various machines have been developed for which loading products into standard top opening boxes (cases or cartons) from the top while the bottom of the box is closed or horizontally from one side or one end or from the bottom while a side, end, or a bottom of the box is open. Such apparatus and methods are disclosed in prior U.S. patents, i.e. U.S. Pat. Nos. 3,605,377; 3,748,813; 4,397,599; 4,481,752; and 4,674,261 all of which are hereby incorporated herein by reference. Box loaders as disclosed in the prior art have several drawbacks. One problem with these prior art loaders which are designed to load a standard top opening case or regular slotted carton (RSC), is that in order for product loading and closure of the bottom flaps of the box to take place it is necessary to move the box in a crosswise or lateral direction requiring additional loader width and increased complexity on changeover. (An RSC has two opposing minor flaps and two opposing major flaps such that when the box is closed the minor flaps are folded and touch upon the product enclosed by the box and the major flaps overlap the minor flaps and meet to provide a relatively uniform surface along the top and bottom surfaces of the box when closed; other types of boxes have flaps that may be non-overlapping or may overlap partially of fully). In these loaders the bottom flaps are closed by moving the case being loaded generally horizontally in a first direction and then in a second direction perpendicular to the first direction, i.e. a lateral movement. The minor flaps (the inner flaps) are folded around a product loading elevator plate which has carried the product into the carton. The minor flaps are folded over the outside edges of the elevator plate capturing both the product and the elevator plate. Then the case (now containing the product) is slid off the elevator plate folding the bottom leading major flap to a second position onto an adjacent support platform where the already folded minor flaps and folded major flap are between the product and the platform. After reaching this second position, the case is moved in a second, lateral, direction perpendicular to the direction of the first motion. When moving in this second direction the major flaps are folded to their closed position by flap folding rods to their closed position and the box is sealed closed by tape or glue.
When tape is used as the closure means, pressure sensitive tape is applied to seal the box after the major flaps are fully closed.
When glue is used as the closure means, hot melt glue is applied to the inner (minor) flaps of the box as the major flaps are simultaneously being folded to their closed position. Once the box has made it through the flap folding rods it reaches a compression position (station) where the top and bottom of the box are pressed closed to hold the major flaps in a closed position for a short time (i.e. 1-5 secs.) to allow the fast setting glue to set holding the major flaps closed.
Another disadvantage of this type of loader is that a box size change is a very complex procedure. The two directions of motion require that two axes of the loader be adjusted and that corner components connecting to both the product loading station and the major flap folding station be non-interferingly adjusted. Accommodation of both adjustments requires a complex mechanism or a large number of interchangeable (changeover) parts. Also, the coordination of box moving mechanisms within the loader is hampered by the wide variability of potential box sizes. There is no central coordination of the many motions of the machine, so as a result many pieces and speed controls have to be changed and modified and/or adjusted in order to accommodate different box sizes and variations in the speed of operation.
When the prior art loaders jam or require maintenance, access for clearing or servicing the loader is complicated by the two axes of motion and their perpendicular paths. Operational clearing might be necessary when a box jams in the loader or the product somehow fails to load properly. Access to loader components and boxes near the center of the machine for both operational and maintenance servicing, at an extreme distance from the access points at the edge of the machines, is difficult.
Speed adjustment of the prior art machines loaders requires adjustment of each operating motion in consecutive order. Nearly all the motions in the prior art machines are powered and controlled primarily by hydraulic and pneumatic systems using hydraulic and pneumatic rams. Speeding up these machines requires that the amount of fluid flowing to each operating element (ram) be checked and/or revised and that these motions be coordinated with operating loads in place. Each ram must be adjusted independently to avoid interference between boxes moving to the direction changing corner of the machine and boxes moving from that corner to the discharge station of the machine. Therefore during operation, any change in speed would have to have been done iteratively and gradually. Or absent actual operation, changes in speed would have to have been evaluated using a simulated load in order to properly gauge the time vs. load response of the hydraulic and/or pneumatic devices.
These disadvantages in prior art bottom flap folding machines discourage changing sizes, unnecessarily complicate operational clearing and maintenance, and make increasing the speed a complex multi-stepped effort.